Process for making a detergent composition by adding co-surfactants

ABSTRACT

A process for continuously preparing a free flowing agglomerate having a reduced level of resulting undesirable oversized granules is provided. The process comprises the steps of (a) thoroughly mixing a crystalline anionic surfactant paste with a sufficient amount of fine powders of starting detergent materials to form a free flowing agglomerate, then (b) thoroughly mixing a product of the step (a) with a non-crystalline anionic surfactant paste so as to form a free flowing agglomerate.

FIELD OF THE INVENTION

The present invention generally relates to a process for producing adetergent composition. More particularly, the invention is directed to anon-tower process during which detergent granules are produced by addingco-surfactants. The process produces a free flowing, detergentcomposition whose density can be adjusted for wide range of consumerneeds, and which can be commercially sold.

BACKGROUND OF THE INVENTION

Recently, there has been considerable interest within the detergentindustry to produce modern detergent compositions for flexibility in theultimate density of the final composition.

Generally, there are three primary types of processes by which detergentgranules or powders can be prepared. The first type of process involvesspray-drying an aqueous detergent slurry in a spray-drying tower toproduce highly porous detergent granules (e.g., tower process for lowdensity detergent compositions). The second type of process involvesspray-drying an aqueous detergent slurry in a spray-drying tower as thefirst step, then, the resultant granules are agglomerated with a bindersuch as a nonionic or anionic surfactant, finally, various detergentcomponents are dry mixed to produce detergent granules (e.g., towerprocess plus non-tower [agglomeration] process for high densitydetergent compositions). In the third type of process, the variousdetergent components are dry mixed after which they are agglomeratedwith a binder such as a nonionic or anionic surfactant, to produce highdensity detergent compositions (e.g., non-tower [agglomeration] processfor high density detergent compositions). In the above three processes,the important factors which govern the density of the resultingdetergent granules are the shape, porosity and particle sizedistribution of said granules, the density of the various startingmaterials, the shape of the various starting materials, and theirrespective chemical composition.

It is often desirable, for performance reasons, to use a mixture ofsurfactants. Such surfactants are typically prepared in the form ofaqueous pastes (typically 25-70% active). When preparing agglomeratedgranules from mixtures of such surfactant pastes, there are twoapproaches generally used. One typical approach is; surfactants in theform of paste are mixed so as to form a co-surfactant paste, followed byagglomerating the paste in a mixer, or in a series of mixers with dryingredients such as builders (e.g. sodium tripolyphosphate), inorganicfillers (e.g. sodium sulfate), bleaches, etc. This approach is notalways desirable in terms of finished product quality. For example,mixing of even a relatively small amount of a non-crystalline surfactantpaste, (i.e. the paste of a type of surfactant which is typically stickyand difficult to be applied in an agglomeration process), with a pasteof a crystalline surfactant, (i.e. a type which is typically easy toapply in an agglomeration process), results in a co-surfactant pastethat has the nature of paste of a non-crystalline surfactant. In otherwords, this type of approach typically causes stickiness of aco-surfactant paste, when co-surfactants include a non-crystallinesurfactant, since such non-crystalline surfactant is generally sticky.Consequently, the granules made by this approach generally include alarge amount of undesirable oversized agglomerates. Some reduction inthe amount of oversize agglomerates can be achieved by using relativelylarge amounts of flow aids such as zeolites and silicates in theagglomeration step. This, however results in added expense. Anothertypical approach is, each type of surfactant is formulated into separateagglomerates and then both agglomerates are blended. This approachtypically is not desirable since the cost for the parallel agglomerationis rather expensive.

Accordingly, there remains a need in the art to have a process forproducing a detergent composition which reduces the level of resultingundesirable oversized agglomerates, when starting detergent materialsinclude a co-surfactant which is non-crystalline. Also, there remains aneed for such a process which is more efficient, flexible and economicalto facilitate large-scale production of detergents for flexibility inthe ultimate density of the final composition.

BACKGROUND ART

The following references are directed to densifying spray-driedgranules: Appel et al, U.S. Pat. No. 5,133,924 (Lever); Bortolotti etal, U.S. Pat. No. 5,160,657 (Lever); Johnson et al, British patent No.1,517,713 (Unilever); and Curtis, European Patent Application 451,894.

The following references are directed to producing detergents byagglomeration: Beerse et al, U.S. Pat. No. 5,108,646 (Procter & Gamble);Capeci et al, U.S. Pat. No. 5,366,652 (Procter & Gamble); Hollingsworthet al, European Patent Application 351,937 (Unilever); and Swatling etal, U.S. Pat. No. 5,205,958.

The Japanese Patent Application, Laid-open No H5-171199 (Lion),describes a high bulk density granular detergent composition comprisinga fatty acid lower alkyl ester sulfonate (“Co-surfactant I”) and ananionic surfactant other than Co-surfactant I, silicate, and carbonate.This composition is disclosed as preventing the hydrolysis ofCo-surfactant I after long term shortage.

SUMMARY OF THE INVENTION

The present invention meets the aforementioned needs in the art byproviding a non-tower process, especially agglomeration process, whichproduces a granular detergent composition having ultimate density of thefinal granular composition. The present process is stable in terms offlow ability and cost effective, since the process reduces the level ofundesirable oversized granules and/or the level of process flow aids,such as zeolites and/or silicates, that prevent over agglomeration.Consequently, the process of the present invention is more efficient,economical and flexible with regard to obtaining detergent compositionshaving less oversized granules (i.e., agglomerates).

As used herein, the term “agglomerates” refers to particles formed byagglomerating raw materials with binder such as surfactants and orinorganic solutions/organic solvents and polymer solutions. As usedherein, the term “crystalline (anionic) surfactant paste” refers to the(anionic) surfactant paste having crystalline structure, generallyhaving about 50-100%, preferably about 65-100%, more preferably about80-100% of crystallinity, measured by X-Ray Diffraction (XRD). As usedherein, the term “non-crystalline (anionic) surfactant paste” refers tothe (anionic) surfactant paste which is not crystalline (anionic)surfactant paste defined as the above. All percentages used herein areexpressed as “percent-by-weight” unless indicated otherwise.

The present invention provides a process for preparing a granulardetergent composition, the process comprising: (a) thoroughly mixing acrystalline anionic surfactant paste with a sufficient amount of finepowders of starting detergent materials form a free flowing agglomerate;(b) thoroughly mixing a product of the step (a) with a non-crystallineanionic surfactant paste to form a free flowing agglomerate; isprovided. An agglomerate from the process of the present invention has areduced level of resulting undesirable oversized granules.

Also provided are the granular detergent compositions produced by anyone of the process embodiments described herein.

Accordingly, it is an object of the invention to provide a process forcontinuously producing a free flowing agglomerate, which reduces thelevel of resulting undesirable oversized granules. It is also an objectof the invention to provide a process which is more efficient, flexibleand economical to facilitate large-scale production of detergents of lowas well as high dosage levels. These and other objects, features andattendant advantages of the present invention will become apparent tothose skilled in the art from a reading of the following detaileddescription of the preferred embodiment and the appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention is directed to a process which produces freeflowing, granular detergent composition by controlling stickinessderived from a non-crystalline surfactant paste.

Process

First Step

In the first step of the process, a crystalline anionic surfactant pasteand finely powdered detergent ingredients (hereinafter, fine powders),such as builders, are fed into an mixing equipment and then areagglomerated by dispersing the surfactant paste onto the fine powders,so as to form a free flowing agglomerate. Optionally, other startingdetergent materials can be also fed into the equipment in this step. Inthis step, the amount of fine powders required to the first step dependson the amount of the crystalline anionic surfactant paste and the watercontent of the paste.

The examples of the equipment for the first step can be any types ofequipment for agglomeration known to those skilled in the art. Asuitable example can be a mixer, such as Lödige CB Mixer, Lödige KMMixer, or Drais K-TTP.

Condition of agglomeration including time period for the first stepdepends on the type of equipment used for the first step, so as toproduce an agglomerated homogeneous mixture. Such conditions can also bedecided based on the design of final composition from the process of thepresent invention.

Second Step

In the second step of the process, the resultant from the first step, anon-crystalline anionic surfactant paste and fine powders are furthermixed together so as to form a free flowing agglomerate. Optionally,other starting detergent materials can be also fed into the equipment inthis step. In this step, the amount of fine powders required to thesecond step depends on the amount of the anionic surfactant paste (i.e.,unreacted paste in the first step and the non-crystalline anionicsurfactant paste), and the water content in the paste. Optionally, finepowders can be added to the second process.

In the second step of the process, a non-crystalline anionic surfactantpaste is added to a resultant from the first step, subsequently, thepaste and the resultant are further agglomerated so as to formgranulates/agglomerates. In the second step, fine powders, either usedin the first step or other fine powders, can be additionally added tothe resultant.

The second step can be undertaken in the equipment for the first step orin another (second) equipment for agglomeration. The examples of theequipment can be any types of mixers known to those skilled in the art.A suitable example can be a mixer, such as Schugi Flexomic Model, LödigeCB Mixer, Lödige KM Mixer or Drais K-T. Generally, the process of thepresent invention allows the mixed crystalline anionic surfactant pastefrom the first step to stand for at least about 0.1 seconds prior toadding the non-crystalline anionic surfactant paste in the second step.

The agglomerated materials during the second step, which includes theanionic crystalline surfactant paste and the anionic non-crystallinesurfactant paste, has a nature similar to agglomerates formed fromcrystalline anionic surfactant paste, namely, less amount of over sizedagglomerates than agglomerates formed from non-crystalline anionicsurfactant paste or formed from a mixture of crystalline surfactantpaste and morphous anionic surfactant paste. Consequently, the secondstep can be undertaken smoothly since the agglomerated material has lessamount of over sized agglomerates. Generally, the agglomerates from thepresent process include less than 20% of particles whose diameter islarger than 1180 μm. Preferably, the agglomerates from the presentprocess include less than 15% of particles whose diameter is larger than1180 μm. More preferably, the agglomerates from the present processinclude less than 10% of particles having diameter larger than about1180 μm.

The resultant from the second step can be processed for furtheragglomeration which is well known to those skilled in the art.

In the present invention, the amount (as an active weight ratio) of thefine powders to the amount of crystalline anionic surfactant in thepaste can be from about 2.0% to about 3.2%, preferably, from about 2.4%to about 2.8%.

In the present invention, the amount (as an active weight ratio) of thecrystalline anionic surfactant in the paste to the amount of thenon-crystalline anionic surfactant in the paste can be from about 4% toabout 14%, preferably, from about 6% to about 12%, more preferably, fromabout 8% to about 10%.

Starting Detergent Materials

Starting detergent materials for granular detergent composition which ismade according to the process of the present invention, except forcrystalline anionic surfactant(s), non-crystalline anionic surfactant(s)and fine powders for the present invention, can be added anytime duringor after the above two steps. Such other starting detergent materialsfully described below.

Detergent Surfactant (Aqueous/Non-aqueous)

The total amount of detergent surfactant (i.e., crystalline anionicsurfactant(s), non-crystalline anionic surfactant(s) and othersurfactants for the final product from the present invention) which canbe used for the present process can be from about 5% to about 60%, morepreferably from about 12% to about 40%, more preferably, from about 15%to about 35%, in total amount of the final product obtained by theprocess of the present invention.

The surfactant itself is preferably selected from anionic, nonionic,zwitterionic, ampholytic and cationic classes and compatible mixturesthereof. Detergent surfactants useful herein are described in U.S. Pat.No. 3,664,961, Norris, issued May 23, 1972, and in U.S. Pat. No.3,929,678, Laughlin et al., issued Dec. 30, 1975, both of which areincorporated herein by reference. Useful cationic surfactants alsoinclude those described in U.S. Pat. No. 4,222,905, Cockrell, issuedSep. 16, 1980, and in U.S. Pat. No. 4,239,659, Murphy, issued Dec. 16,1980, both of which are also incorporated herein by reference. Of thesurfactants, anionics and nonionics are preferred and anionics are mostpreferred.

Nonlimiting examples of the preferred anionic surfactants useful in thepresent invention include the conventional C₁₁-C₁₈ alkyl benzenesulfonates (“LAS”), primary, branched-chain and random C₁₀-C₂₀ alkylsulfates (“AS”), the C₁₀-C₁₈ secondary (2,3) alkyl sulfates of theformula CH₃(CH₂)_(x)(CHOSO₃ ⁻M⁺)CH₃ and Ch₃ (CH₂)y(CHOSO₃ ⁻M⁺) CH₂CH₃where x and (y+1) are integers of at least about 7, preferably at leastabout 9, and M is a water-solubilizing cation, especially sodium,unsaturated sulfates such as oleyl sulfate, and the C₁₀-C₁₈ alkyl alkoxysulfates (“AE_(x)S”; especially EO 1-7 ethoxy sulfates).

Useful anionic surfactants also include water-soluble salts of2-acyloxyalkane-1-sulfonic acids containing from about 2 to 9 carbonatoms in the acyl group and from about 9 to about 23 carbon atoms in thealkane moiety; water-soluble salts of olefin sulfonates containing fromabout 12 to 24 carbon atoms; and beta-alkyloxy alkane sulfonatescontaining from about 1 to 3 carbon atoms in the alkyl group and fromabout 8 to 20 carbon atoms in the alkane moiety.

Among these anionic surfactants, the preferable examples as crystallineanionic surfactant paste(s) of the present invention include; eithernatural or synthetic alkyl sulfates, preferably, C₁₂-C₁₈ coconut fattyalcohol sulfates or C₁₄-C₁₅ synthetic alkyl sulfates. The preferableexamples as non-crystalline anionic surfactant paste(s) of the presentinvention include; alkyl alkoxy sulfates (AE_(x)S), alkyl benzenesulfonates (LAS).

Optionally, other exemplary surfactants useful in the paste of theinvention include C₁₀-C₁₈ alkyl alkoxy carboxylates (especially the EO1-5 ethoxycarboxylates), the C₁₀₋₁₈ glycerol ethers, the C₁₀-C₁₈ alkylpolyglycosides and the corresponding sulfated polyglycosides, andC₁₂-C₁₈ alpha-sulfonated fatty acid esters. If desired, the conventionalnonionic and amphoteric surfactants such as the C₁₂-C₁₈ alkylethoxylates (“AE”) including the so-called narrow peaked alkylethoxylates and C₆-C₁₂ alkyl phenol alkoxylates (especially ethoxylatesand mixed ethoxy/propoxy), C₁₀-C₁₈ amine oxides, and the like, can alsobe included in the overall compositions. The C₁₀-C₁₈ N-alkyl polyhydroxyfatty acid amides can also be used. Typical examples include the C₁₂-C₁₈N-methylglucamides. See WO 9,206,154. Other sugar-derived surfactantsinclude the N-alkoxy polyhydroxy fatty acid amides, such as C₁₀-C₁₈N-(3-methoxypropyl) glucamide. The N-propyl through N-hexyl C₁₂-C₁₈glucamides can be used for low sudsing. C₁₀-C₂₀ conventional soaps mayalso be used. If high sudsing is desired, the branched-chain C₁₀-C₁₆soaps may be used. Mixtures of anionic and nonionic surfactants areespecially useful. Other conventional useful surfactants are listed instandard texts.

Cationic surfactants can also be used as a detergent surfactant hereinand suitable quaternary ammonium surfactants are selected from monoC₆-C_(16,) preferably C₆-C₁₀ N-alkyl or alkenyl ammonium surfactantswherein remaining N positions are substituted by methyl, hydroxyethyl orhydroxypropyl groups.

Ampholytic surfactants can also be used as a detergent surfactantherein, which include aliphatic derivatives of heterocyclic secondaryand tertiary amines; zwitterionic surfactants which include derivativesof aliphatic quaternary ammonium, phosphonium and sulfonium compounds;water-soluble salts of esters of alpha-sulfonated fatty acids; alkylether sulfates; water-soluble salts of olefin sulfonates; beta-alkyloxyalkane sulfonates; betaines having the formula R(R¹)₂N⁺R²COO⁻, wherein Ris a C₆-C₁₈ hydrocarbyl group, preferably a C₁₀-C₁₆ alkyl group orC₁₀-C₁₆ acylamido alkyl group, each R¹ is typically C₁-C₃ alkyl,preferably methyl and R₂ is a C₁-C₅ hydrocarbyl group, preferably aC₁-C₃ alkylene group, more preferably a C₁-C₂ alkylene group. Examplesof suitable betaines include coconut acylamidopropyidimethyl betaine;hexadecyl dimethyl betaine; C₁₂₋₁₄ acylamidopropylbetaine; C₈₋₁₄acylamidohexyldiethyl betaine; 4[C₁₄₋₁₆acylmethylamidodiethylammonio]-1- carboxybutane; C₁₆₋₁₈acylamidodimethylbetaine; C₁₂₋₁₆ acylamidopentanediethylbetaine; andC₁₂₋₁₆ acylmethylamidodimethylbetaine. Preferred betaines are C₁₂₋₁₈dimethylammonio hexanoate and the C₁₀₋₁₈ acylamidopropane (or ethane)dimethyl (or diethyl) betaines; and the sultaines having the formula(R(R¹)₂N⁺R²SO₃— wherein R is a C₆-C₁₈ hydrocarbyl group, preferably aC₁₀-C₁₆ alkyl group, more preferably a C₁₂-C₁₃ alkyl group, each R¹ istypically C₁-C₃ alkyl, preferably methyl, and R² is a C₁-C₆ hydrocarbylgroup, preferably a C₁-C₃ alkylene or, preferably, hydroxyalkylenegroup. Examples of suitable sultaines include C₁₂-C₁₄dimethylammonio-2-hydroxypropyl sulfonate, C₁₂-C₁₄ amido propylammonio-2-hydroxypropyl sultaine, C₁₂-C₁₄ dihydroxyethylammonio propanesulfonate, and C₁₆₋₁₈ dimethylammonio hexane sulfonate, with C₁₂₋₁₄amido propyl ammonio-2-hydroxypropyl sultaine being preferred.

Fine Powders

The fine powders of the present process preferably selected from thegroup consisting of ground soda ash, powdered sodium tripolyphosphate(STPP), hydrated tripolyphosphate, ground sodium sulphates,aluminosilicates, crystalline layered silicates, nitrilotriacetates(NTA), phosphates, precipitated silicates, polymers, carbonates,citrates, powdered surfactants (such as powdered alkane sulfonic acids)and recycle fines occurring from the process of the present invention,wherein the average diameter of the powder is from 0.1 to 500 microns,preferably from 1 to 300 microns, more preferably from 5 to 100 microns.In the case of using hydrated STPP as the fine powders of the presentinvention, STPP which is hydrated to a level of not less than 50% ispreferable. The aluminosilicate ion exchange materials used herein as adetergent builder preferably have both a high calcium ion exchangecapacity and a high exchange rate. Without intending to be limited bytheory, it is believed that such high calcium ion exchange rate andcapacity are a function of several interrelated factors which derivefrom the method by which the aluminosilicate ion exchange material isproduced. In that regard, the aluminosilicate ion exchange materialsused herein are preferably produced in accordance with Corkill et al,U.S. Pat. No. 4,605,509 (Procter & Gamble), the disclosure of which isincorporated herein by reference.

Preferably, the aluminosilicate ion exchange material is in “sodium”form since the potassium and hydrogen forms of the instantaluminosilicate do not exhibit as high of an exchange rate and capacityas provided by the sodium form. Additionally, the aluminosilicate ionexchange material preferably is in over dried form so as to facilitateproduction of crisp detergent agglomerates as described herein. Thealuminosilicate ion exchange materials used herein preferably haveparticle size diameters which optimize their effectiveness as detergentbuilders. The term “particle size diameter” as used herein representsthe average particle size diameter of a given aluminosilicate ionexchange material as determined by conventional analytical techniques,such as microscopic determination and scanning electron microscope(SEM). The preferred particle size diameter of the aluminosilicate isfrom about 0.1 micron to about 10 microns, more preferably from about0.5 microns to about 9 microns. Most preferably, the particle sizediameter is from about 1 microns to about 8 microns.

Preferably, the aluminosilicate ion exchange material has the formula

Na_(z)[(AlO₂)_(z).(SiO₂)_(y) ]xH₂O

wherein z and y are integers of at least 6, the molar ratio of z to y isfrom about 1 to about 5 and x is from about 10 to about 264. Morepreferably, the aluminosilicate has the formula

Na₁₂[(AlO₂)₁₂.(SiO₂)₁₂ ]xH₂O

wherein x is from about 20 to about 30, preferably about 27. Thesepreferred aluminosilicates are available commercially, for example underdesignations Zeolite A, Zeolite B and Zeolite X. Alternatively,naturally-occurring or synthetically derived aluminosilicate ionexchange materials suitable for use herein can be made as described inKrummel et al, U.S. Pat. No. 3,985,669, the disclosure of which isincorporated herein by reference.

The aluminosilicates used herein are further characterized by their ionexchange capacity which is at least about 200 mg equivalent of CaCO₃hardness/gram, calculated on an anhydrous basis, and which is preferablyin a range from about 300 to 352 mg equivalent of CaCO₃ hardness/gram.Additionally, the instant aluminosilicate ion exchange materials arestill further characterized by their calcium ion exchange rate which isat least about 2 grains Ca⁺⁺/gallon/minute/-gram/gallon, and morepreferably in a range from about 2 grainsCa⁺⁺/gallon/minute/-gram/gallon to about 6 grains Ca⁺⁺/gallon/minute/gram/gallon.

Liquid Polymers

The starting detergent material for the present process can includeliquid polymers. The liquid polymers can be selected from aqueous ornon-aqueous polymer solutions, water and mixtures thereof. The amount ofliquid polymers of the present process can be lower than about 10%(active basis), preferably lower than about 6% (active basis) in totalamount of the final product obtained by the process of the presentinvention.

Preferable examples of the aqueous or non-aqueous polymer solutionswhich can be used in the present inventions are modified polyamineswhich coprise a polyamine backbone corresponding to the formula:

having a modified polyamine formula V_((n+1))W_(m)Y_(n)Z or a polyaminebackbone corresponding to the formula:

having a modified polyamine formula V_((n-k+1))W_(m)Y_(n)Y′_(k)Z,wherein k is less than or equal to n, said polyamine backbone prior tomodification has a molecular weight greater than about 200 daltons,wherein

i) V units are terminal units having the formula:

ii) W units are backbone units having the formula:

iii) Y units are branching units having the formula:

iv) Z units are terminal units having the formula:

wherein backbone linking R units are selected from the group consistingof C₂-C₁₂ alkylene, C₄-C₁₂ alkenylene, C₃-C₁₂ hydroxyalkylene, C₄-C₁₂dihydroxy-alkylene, C₈-C₁₂ dialkylarylene, —(R¹O)_(x)R¹—,—(R¹O)_(x)R⁵(OR¹) _(x)—,—(CH₂CH(OR²)CH₂O)_(z)(R¹O)_(y)R¹(OCH₂CH(OR²)CH₂)_(w)—,—C(O)(R⁴)_(r)C(O)—, —CH₂CH(OR²)CH₂—, and mixtures thereof; wherein R¹ isC₂-C₆ alkylene and mixtures thereof; R² is hydrogen, —(R¹O)_(x)B, andmixtures thereof; R³ is C₁-C₁₈ alkyl, C₇-C₁₂ arylalkyl, C₇C₁₂ alkylsubstituted aryl, C₆-C₁₂ aryl, and mixtures thereof; R⁴ is C₁-C₁₂alkylene, C₄-C₁₂ alkenylene, C₈-C₁₂ arylalkylene, C₆-C₁₀ arylene, andmixtures thereof; R⁵ is C₁-C₁₂ alkylene, C₃-C₁₂ hydroxyalkylene, C₄-C₁₂dihydroxy-alkylene, C₈-C₁₂ dialkylarylene, —C(O)—, —C(O)NHR⁶NHC(O)—,—R¹(OR¹)—, —C(O)(R⁴)_(r)C(O)—, CH₂CH(OH)CH₂—,—CH₂CH(OH)CH₂O(R¹O)_(y)R¹OCH₂CH(OH)CH₂—, and mixtures thereof; R⁶ isC₂-C₁₂ alkylene or C₆-C₁₂ arylene; E units are selected from the groupconsisting of hydrogen, C₁-C₂₂ alkyl, C₃-C₂₂ alkenyl, C₇-C₂₂ arylalkyl,C₂-C₂₂ hydroxyalkyl, —(CH₂)_(p)CO₂M, —(CH₂)_(q)SO₃M, —CH(CH₂CO₂M)CO₂M,—(CH₂)_(p)PO₃M, —(R¹O)_(x)B, —C(O)R³, and mixtures thereof; oxide: B ishydrogen, C₁-C₆ alkyl, —(CH₂)_(q)SO₃M, —(CH₂)_(p)CO₂M,—(CH₂)_(q)(CHSO₃M) CH₂SO₃M, —(CH₂)_(q)—(CHSO₂M)CH₂SO₃M, —(CH₂)_(p)PO₃M,—PO₃M, and mixtures thereof; M is hydrogen or a water soluble cation insufficient amount to satisfy charge balance; X is a water soluble anion;m has the value from 4 to about 400; n has the value from 0 to about200; p has the value from 1 to 6, q has the value from 0 to 6; r has thevalue of 0 or 1; w has the value 0 or 1; x has the value from 1 to 100;y has the value from 0 to 100; z has the value 0 or 1. One example ofthe most preferred polyethyieneimines would be a polyethyleneiminehaving a molecular weight of 1800 which is further modified byethoxylation to a degree of approximately 7 ethyleneoxy residues pernitrogen (PEI 1800, E7). It is preferable for the above polymer solutionto be pre-complex with anionic surfactant such as NaLAS.

Other preferable examples of the aqueous or non-aqueous polymersolutions which can be used as liquid polymers in the present inventionsare polymeric polycarboxylate dispersants which can be prepared bypolymerizing or copolymerizing suitable unsaturated monomers, preferablyin their acid form. Unsaturated monomeric acids that can be polymerizedto form suitable polymeric polycarboxylates include acrylic acid, maleicacid (or maleic anhydride), fumaric acid, itaconic acid, aconitic acid,mesaconic acid, citraconic acid and methylenemalonic acid. The presencein the polymeric polycarboxylates herein of monomeric segments,containing no carboxylate radicals such as vinylmethyl ether, styrene,ethylene, etc. is suitable provided that such segments do not constitutemore than about 40% by weight.

Homo-polymeric polycarboxylates which have molecular weights above 4000,such as described next are preferred. Particularly suitablehomo-polymeric polycarboxylates can be derived from acrylic acid. Suchacrylic acid-based polymers which are useful herein are thewater-soluble salts of polymerized acrylic acid. The average molecularweight of such polymers in the acid form preferably ranges from above4,000 to 10,000, preferably from above 4,000 to 7,000, and mostpreferably from above 4,000 to 5,000. Water-soluble salts of suchacrylic acid polymers can include, for example, the alkali metal,ammonium and substituted ammonium salts.

Co-polymeric polycarboxylates such as an acrylic/maleic-based copolymersmay also be used. Such materials include the water-soluble salts ofcopolymers of acrylic acid and maleic acid. The average molecular weightof such copolymers in the acid form preferably ranges from about 2,000to 100,000, more preferably from about 5,000 to 75,000, most preferablyfrom about 7,000 to 65,000. The ratio of acrylate to maleate segments insuch copolymers will generally range from about 30:1 to about 1:1, morepreferably from about 10:1 to 2:1. Water-soluble salts of such acrylicacid/maleic acid copolymers can include, for example, the alkali metal,ammonium and substituted ammonium salts. It is preferable for the abovepolymer solution to be pre-complexed with anionic surfactant such asLAS.

Adjunct Detergent Ingredients

The starting detergent material in the present process can includeadditional detergent ingredients and/or, any number of additionalingredients can be incorporated in the detergent composition duringsubsequent steps of the present process. These adjunct ingredientsinclude other detergency builders, bleaches, bleach activators, sudsboosters or suds suppressors, anti-tarnish and anticorrosion agents,soil suspending agents, soil release agents, germicides, pH adjustingagents, non-builder alkalinity sources, chelating agents, smectiteclays, enzymes, enzyme-stabilizing agents and perfumes. See U.S. Pat.No. 3,936,537, issued Feb. 3, 1976 to Baskerville, Jr. et al.,incorporated herein by reference.

Other builders can be generally selected from the various water-soluble,alkali metal, ammonium or substituted ammonium phosphates,polyphosphates, phosphonates, polyphosphonates, carbonates, borates,polyhydroxy sulfonates, polyacetates, carboxylates, andpolycarboxylates. Preferred are the alkali metal, especially sodium,salts of the above. Preferred for use herein are the phosphates,carbonates, C₁₀₋₁₈ fatty acids, polycarboxylates, and mixtures thereof.More preferred are sodium tripolyphosphate, tetrasodium pyrophosphate,citrate, tartrate mono- and di-succinates, and mixtures thereof.

Bleaching agents and activators are described in U.S. Pat. No.4,412,934, Chung et al., issued Nov. 1, 1983, and in U.S. Pat. No.4,483,781, Hartman, issued Nov. 20, 1984, both of which are incorporatedherein by reference. Chelating agents are also described in U.S. Pat.No. 4,663,071, Bush et al., from Column 17, line 54 through Column 18,line 68, incorporated herein by reference. Suds modifiers are alsooptional ingredients and are described in U.S. Pat. No. 3,933,672,issued Jan. 20, 1976 to Bartoletta et al., and U.S. Pat. No. 4,136,045,issued Jan. 23, 1979 to Gault et al., both incorporated herein byreference.

Suitable smectite clays for use herein are described in U.S. Pat. No.4,762,645, Tucker et al, issued Aug. 9, 1988, Column 6, line 3 throughColumn 7, line 24, incorporated herein by reference. Suitable additionaldetergency builders for use herein are enumerated in the Baskervillepatent, Column 13, line 54 through Column 16, line 16, and in U.S. Pat.No. 4,663,071, Bush et al, issued May 5, 1987, both incorporated hereinby reference.

Optional Process Steps

One optional step after the second step of the present invention is anadditional agglomeration process. The examples which can be used as theadditional process are described in such as U.S. Pat. No. 5,486,303,U.S. Pat. No. 5,516,448, U.S. Pat. No. 5,554,587 and U.S. Pat. No.5,574,005.

Other optional step in the process is drying, if it is desired to reducelevel of moisture from the present process. This can be accomplished bya variety of apparatus, well known to these skilled in the art. Fluidbed apparatus is preferred, and will be referred to in the discussionwhich follows.

In other optional step of the present process, the detergent granulesexiting the fluid bed dryer are further conditioned by additionalcooling in cooling apparatus. The preferred apparatus is a fluid bed.Another optional process step involves adding a coating agent to improveflowability in one or more of the following locations of the instantprocess. The coating agent is preferably selected from the groupconsisting of aluminosilicates, silicates, carbonates and mixturesthereof. The coating agent not only enhances the free flowability of theresulting detergent composition which is desirable by consumers in thatit permits easy scooping for detergent during use, but also serves tocontrol agglomeration by preventing or minimizing over agglomeration,especially when added directly to the moderate speed mixer. As thoseskilled in the art are well aware, over agglomeration can lead to veryundesirable flow properties and aesthetics of the final detergentproduct.

Optionally, the process can comprise the step of spraying an additionalbinder in the process for the present invention or fluid bed dryersand/or fluid bed coolers. A binder is added for purposes of enhancingagglomeration by providing a “binding” or “sticking” agent for thedetergent components. The binder is preferably selected from the groupconsisting of water, anionic surfactants, nonionic surfactants, liquidsilicates, polyethylene glycol, polyvinyl pyrrolidone polyacrylates,citric acid and mixtures thereof. Other suitable binder materialsincluding those listed herein are described in Beerse et al, U.S. Pat.No. 5,108,646 (Procter & Gamble Co.), the disclosure of which isincorporated herein by reference.

Other optional steps contemplated by the present process includescreening the oversized detergent granules, whose amount is minimized bythe present process, in a screening apparatus which can take a varietyof forms including but not limited to conventional screens chosen forthe desired particle size of the finished detergent product.

Another optional step of the instant process entails finishing theresulting detergent agglomerates by a variety of processes includingspraying and/or admixing other conventional detergent ingredients. Forexample, the finishing step encompasses spraying perfumes, brightenersand enzymes onto the finished agglomerates to provide a more completedetergent composition. Such techniques and ingredients are well known inthe art.

The other optional step in the process involves high active pastestructuring process, e.g., hardening an aqueous anionic surfactant pasteby incorporating a paste-hardening material by using an extruder, priorto the process of the present invention. The details of the high activepaste structuring process is disclosed application No. PCT/US96/15960(filed Oct. 4,1996).

In order to make the present invention more readily understood,reference is made to the following examples, which are intended to beillustrative only and not intended to be limiting in scope.

EXAMPLES Example 1

The following is an example* (*: batch size) for obtaining agglomeratesusing a bench scale sized Lodige CB mixer (hereinafter, CB mixer).

232 g of CFAS (coconut fatty alcohol sulfate, C₁₂-C₁₈) paste (72%active) is dispersed by the pin tools of a CB mixer for 7.25 seconds,along with 179 g of powdered STPP (mean particle size of 40-75 microns),119 of ground soda ash (mean particle size of 10-20 microns), 92 g ofsodium sulfate (mean particle size of 70-120 microns), 37 of zeolite and140 of recycle fines. After a short interval (1-2 seconds), 26 g of AE₃S(alkyl ethoxy sulfate, C12-C15) paste (70% active) is dispersed by thepin tools of the CB mixer for about 1 second. After the addition of AE₃Spaste, the contents in the CB mixer are mixed for about 3 seconds inorder to obtain free-flowing agglomerates.

The condition of the CB mixer is as follows:

Mixer speed : 800 rpm

Paste temperature: 45-47° C.

Jacket temperature: 30° C.

Pin length: 18.9 cm

Diameter of the mixer: 20 cm

The agglomerate from the CB mixer has free-flowing, density of 640-700g/l. The agglomerates includes only 5.2% of oversized (i.e., larger than1180 μm m) granules.

Example 2

The following is an example* (*: batch size) for obtaining agglomeratesusing a bench scale sized Lödige CB mixer (hereinafter, CB mixer),followed by bench scale sized Lödige KM mixer (hereinafter, KM mixer).

234 g of CFAS (coconut fatty alcohol sulfate, C₁₂-C₁₈) paste (72%active) is dispersed by the pin tools of a CB mixer for 7.5 seconds,along with 197 g of powdered STPP (mean particle size of about 40-75microns), 152 g of ground soda ash (mean particle size of about 10-20microns), 66 g of sodium sulfate (mean particle size of about 10-20microns) and 136 g of recycle fines. The contents in the CB mixer aremixed for about 4 seconds in order to obtain free-flowing agglomerates.The conditions of the CB-30 mixers are as follows.

Mixer speed: 800 rpm

Paste temperature: 45-47° C.

Jacket temperature: 30° C.

Pin length: 18.9 cm

Diameter of the mixer: 20 cm

750 g of the agglomerates from the CB mixer is added to the KM mixer. 29g of acid precursor of LAS (linear alkyl benzene sulfonate, C₁₈(=average)) at 50-60° C. is added to a KM mixer for about 1.5 seconds.After the addition of acid precursor of LAS, 8 g bf zeolite (meanparticle size of about 4-7 microns) and 50 g of ground soda ash (meanparticle size of about 10-20 microns) is added. The contents are mixedin the KM mixer for 4-5 seconds, for the purpose of particle growth. Inthis mixing step, optionally, one or more conventional choppers can beattached into the KM mixer.

The conditions of the KM mixer are as follows:

Mixer speed: 150 rpm

Jacket temperature : 35° C.

The agglomerates obtained from the KM mixer are dried in a batch scalefluid bed dryer at 95° C. for 3 minutes, and subsequently cooled in abatch scale fluid bed cooler.

The agglomerates from the cooler are free-flowing with a cake strengthof about 0.7 kgf, and has density of 750-800 g/l. The mean particle sizeof agglomerates is about 400-500 μm. The agglomerates includes about 20%of unacceptable oversized (i.e., larger than 1180 μm) agglomerates.

Example 3

The following is an example for obtaining agglomerates using LödigeCB-30 mixer (hereinafter, CB mixer), followed by Lödige KM-600 mixer(hereinafter, KM mixer).

340 kg/hr of CFAS (coconut fatty alcohol sulfate, C₁₂-C₁₈) paste (72%active) is dispersed by the pin tools of a CB mixer along with 250 kg/hrof powdered STPP (mean particle size of about 40-75 microns), 185 kg/hrof ground soda ash (mean particle size of about 10-20 microns), 195kg/hr of ground sulfate (mean particle size of about 10-20 microns), 200kg/hr of recycle fines and 11 kg/hr of zeolite. The conditions of theCB-30 mixer are as follows.

Mixer speed : 620 rpm

Paste temperature: 45-48° C.

Jacket temperature: 30° C.

Pin length : 28.9 cm

Diameter of the mixer: 30 cm

Retention time : 7-15 seconds

Energy condition of the Mixer: 2.1 kj/kg

The agglomerates from the CB mixer is added to the KM mixer. 37 kg/hr ofAE₃S (alkyl ethoxy sulfate, C₁₂-C₁₅) paste (70% active) is dispersed toKM mixer by the pin tools of the CB mixer. 5-10 kg/hr of Zeolite isadded to the KM mixer. In the mixing step in KM mixer, conventionalchoppers (4 numbers of “Christmas Tree Choppers”) can be attached intothe KM mixer.

The conditions of the KM mixer are as follows:

Mixer speed: 100 rpm

Jacket temperature : 40° C.

Retention time: 2.0-6.0 minutes

Energy condition of the Mixer: 1.5-3.0 kj/kg

Condition of choppers: 1,600 rpm

The agglomerates obtained from the KM mixer has only about 2-10% ofunacceptable oversized (i.e., larger than 1180 μm) agglomerates. Theagglomerates from the KM mixer (having diameter not larger than 1180 μm)are dried in a fluid bed dryer at 95° C., and subsequently cooled at10-12 ° C. in a fluid bed cooler.

The agglomerates from the cooler are free-flowing, and has density of750-850 g/l. The mean particle size of agglomerates is about 500-650 μm.

Having thus described the invention in detail, it will be obvious tothose skilled in the art that various changes may be made withoutdeparting from the scope of the invention and the invention is not to beconsidered limited to what is described in the specification.

What is claimed is:
 1. A process for preparing a granular detergentcomposition comprising: (a) thoroughly mixing a crystalline anionicsurfactant paste selected from the group consisting of C₁₂-C₁₈ coconutfatty alcohol sulfates, C₁₄C₁₅ synthetic alkyl sulfates and mixturesthereof, with a sufficient amount of fine powders selected from thegroup consisting of soda ash, sodium sulphates, aluminosilicates,crystalline layered silicates, phosphates, precipitated silicates,polymers, carbonates, citrates, nitrilotriacetates, powderedsurfactants, recycle fines of fine powders and/or free flowingagglomerates and mixtures thereof, to form a free flowing agglomerate;(b) thoroughly mixing a product of the step (a) with a non-crystallineanionic surfactant paste selected from the group consisting of alkylethoxy sulfates, alkyl benzene sulfonates and mixtures thereof, to forma free flowing agglomerate, wherein the agglomerate from step (b)includes less than about 20% of granules having a diameter larger than1180 μm.
 2. A granular detergent composition made according to theprocess of claim 1.